(i) Technical Field
The present invention relates to a vertical cavity surface emitting laser, a vertical cavity surface emitting laser device, and an optical transmission device.
(ii) Related Art
A vertical cavity surface emitting laser (VCSEL) is used as a light source in a communication device and an image forming apparatus. Typical selective oxidation type vertical cavity surface emitting lasers locate a current confining layer where an oxidized aperture is formed with selective oxidization in the structure of a vertical resonator. An oxidized aperture has a function of injecting current with high density into an active region, and a function of confining the light generated in the active region in a light emission center by using a difference between refractive indexes of the inside and the outside of the oxidized aperture. Single lateral mode is preferable for a vertical cavity surface emitting laser used as a light source in a electronic apparatus. Therefore, a diameter of an oxidized aperture is designed to be small.